This invention relates to pharmaceutical compositions in unit dosage form comprising a pharmaceutically active medicament compound and a flexible, water-soluble film carrier therefor adapted for enteral or topical administration.
Belgian Patent Specification No. 637,363 describes paper films coated with pharmaceutically active medicinal compounds suitable for oral administration. The films comprise water-insoluble cellulose fibers and a water-soluble binding agent, preferably sodium carboxymethyl cellulose. In the examples thereof the pharmaceutically active compound is applied to the paper film by dripping a solution thereof onto the film, depositing the solid active compound on the surface thereof or by drawing the film through a solution of the active medicament. Using the film drawing machines prescribed in this patent, non-uniform layers of film are formed which shrink upon drying. In the alternative techniques described, the discontinuous process of separately making the film and applying the active medicament thereon has inherent disadvantages which prevent high accuracy in the dosages applied. This is of particular importance with the small doses of medicaments often employed in current pharmacy. Inaccuracies inherently arise not only in applying the active medicament, but also in the manufacture and pre-treatment of the carrier and in variations encountered during subsequent storage of the impregnated carrier material. As a non-uniform material is used as the carrier, the subsequent take-up of active medicament is also inherently non-uniform. Moreover, active medicaments bound only on the surface of the films can readily be removed therefrom during subsequent handling, e.g., in packaging. Furthermore, the carboxymethyl cellulose binding agent becomes detached in the stomach, liberating carboxymethyl cellulose from the carrier which entraps some of the active medicament and liberates it only very slowly, if at all.